The invention relates to a device for fastening an article, disposed at an end of a cylindrical shaft portion, to one coupling member of a coupling means whose other coupling member is anchored at a machine tool, especially a die sinking electric discharge machine, the one coupling member comprising a bore to take up the shaft portion.
The applicant's earlier German patent application DE-P 37 06 123 discloses a device for connecting a shaft which carries a sinker electrode to a coupling member which is anchored at a machine tool, especially a die sinking spark erosion machine, and has a conical recess converging from the opening toward the coupling face.
A split insert bushing is provided within the recess and has its inner surface adapted to the outer contour of the shaft so as to press together the coupling member and the shaft.
Furthermore, a fastening means for tools in spark erosion machinery is known from DE-PS 26 46 951. Here, a shaft to be clamped in a chuck is provided with a radially projecting pin which is adapted to be pressed by a spring loaded tensioning member against the end face of the take-up part of the shaft and against a bolt protruding from the take-up part in parallel with the shaft.
The abutment of the pin against the end face of the chuck provides fixation in height and the abutment of the pin against the bolt fixes the angular position. This fastening means, however, has the disadvantage that, for abutment and fixation in height, the pin must be fitted on the shaft, i.e. must be shrunk and/or secured by a grub screw, in other words mounted on the shaft as an additional component part. Furthermore, in that case the electrode is soldered to the shaft and that is expensive in terms of work to be done and further results in the electrode becoming loose from the shaft upon heating.